Barcodes are used for product management purposes. Since amount of information which can be held by a one-dimensional barcode is small, a two-dimensional barcode was invented.
For example, Patent Document 1 describes a two-dimensional barcode. When using a code holding information, the code may not be able to be read. Therefore, in the one-dimensional barcode, numbers which can be read by human eyes are written together at the bottom of the barcode. Further, error correction technology is used to the two-dimensional barcode to cope with lack of information held by the code.